Breast cancer risk among thyroid cancer survivors and the role of I-131 treatment

BACKGROUND

Female thyroid cancer survivors are more likely to have a higher risk of breast cancer compared to the general population, and the underlying causes are yet to be understood. The potential role of I-131 treatment on this association remains controversial.

METHODS

We pooled individual data of women who were treated for differentiated thyroid cancer from 1934 to 2005 in France, Italy and Sweden. Standardized incidence ratios (SIRs) for breast cancer were estimated by comparison with age, sex and calendar-year expected values of the general population in each country. We estimated breast cancer risk in relation to I-131 treatment using time-dependent Poisson models.

RESULTS

Of 8475 women (mean age at diagnosis: 45 years, range 2-90 years), 335 were diagnosed with breast cancer [SIR = 1.52, 95% confidence interval (CI): 1.36-1.69] during a median follow-up time of 12.7 years since diagnosis. Overall, breast cancer risk did not differ between women treated or not with I-131 (relative risk=1.07, 95% CI 0.84-1.35). However, breast cancer risk increased with increasing cumulative I-131 activity, without significant departure from linearity (excess relative risk per 100 mCi=17%, 95% CI: 2% to 38%). The higher risk associated with a cumulative I-131 activity of ≥100 mCi and ≥400 mCi was translated into 4 (95% CI -4 to 13) and 42 (95% CI -8 to 93) excess breast cancer cases per 10,000 person-years, respectively.

CONCLUSIONS

An elevated risk was observed for the highest cumulative administered activity (>=400 mCi), and a significant dose-dependent association was observed among thyroid cancer survivors who were treated with I-131. However, overall, I-131 treatment might only explain partly the increase in breast cancer risk among female thyroid cancer survivors.

One-year COVID-19 outcomes on the oncology care patient pathway: Results of a French descriptive, cross-sectional comprehensive study (ONCOCARE-COV)

BACKGROUND

The COVID-19 pandemic led to a widely documented disruption in cancer care pathway. Since a resurgence of the pandemic was expected after the first lockdown in France, the global impact on the cancer care pathway over the year 2020 was investigated.

AIMS

This study aimed to describe the changes in the oncology care pathway for cancer screening, diagnosis, assessment, diagnosis annoucement procedure and treatment over a one-year period.

MATERIALS & METHODS

The ONCOCARE-COV study was a comprehensive, retrospective, descriptive, and cross-sectional study comparing the years 2019 and 2020. All key indicators along the cancer care pathway assessing the oncological activity over four periods were described. This study was set in a high-volume, public, single tertiary care center divided in two complementary sites (Reims University Hospital and Godinot Cancer Institute, Reims, France) which was located in a high COVID-19 incidence area during both peaks of the outbreak.

RESULTS

A total of 26,566 patient's files were active during the year 2020. Breast screening (-19.5%), announcement dedicated consultations (-9.2%), Intravenous and Hyperthermic Intraoperative Intraperitoneal Chemotherapy (HIPECs) (-25%), and oncogeriatric evaluations (-14.8%) were heavily disrupted in regard to 2020 activity. We identified a clear second outbreak wave impact on medical announcement procedures (October, -14.4%), radiotherapy sessions (October, -16%), number of new health record discussed in multidisciplinary tumor board meeting (November, -14.6%) and HIPECs (November, -100%). Moreover, 2020 cancer care activity stagnated compared to 2019.

DISCUSSION

The oncological care pathway was heavily disrupted during the first and second peaks of the COVID-19 outbreak. Between lockdowns, we observed a remarkable but non-compensatory recovery as well as a lesser impact from the pandemic resurgence. However, in absence of an increase in activity, a backlog persisted.

CONCLUSION

Public health efforts are needed to deal with the consequences of the COVID-19 pandemic on the oncology care pathway.

Thyroidectomy without Radioiodine in Patients with Low-Risk Thyroid Cancer

BACKGROUND

In patients with low-risk differentiated thyroid cancer undergoing thyroidectomy, the postoperative administration of radioiodine (iodine-131) is controversial in the absence of demonstrated benefits.

METHODS

In this prospective, randomized, phase 3 trial, we assigned patients with low-risk differentiated thyroid cancer who were undergoing thyroidectomy to receive ablation with postoperative administration of radioiodine (1.1 GBq) after injections of recombinant human thyrotropin (radioiodine group) or to receive no postoperative radioiodine (no-radioiodine group). The primary objective was to assess whether no radioiodine therapy was noninferior to radioiodine therapy with respect to the absence of a composite end point that included functional, structural, and biologic abnormalities at 3 years. Noninferiority was defined as a between-group difference of less than 5 percentage points in the percentage of patients who did not have events that included the presence of abnormal foci of radioiodine uptake on whole-body scanning that required subsequent treatment (in the radioiodine group only), abnormal findings on neck ultrasonography, or elevated levels of thyroglobulin or thyroglobulin antibodies. Secondary end points included prognostic factors for events and molecular characterization.

RESULTS

Among 730 patients who could be evaluated 3 years after randomization, the percentage of patients without an event was 95.6% (95% confidence interval [CI], 93.0 to 97.5) in the no-radioiodine group and 95.9% (95% CI, 93.3 to 97.7) in the radioiodine group, a difference of -0.3 percentage points (two-sided 90% CI, -2.7 to 2.2), a result that met the noninferiority criteria. Events consisted of structural or functional abnormalities in 8 patients and biologic abnormalities in 23 patients with 25 events. Events were more frequent in patients with a postoperative serum thyroglobulin level of more than 1 ng per milliliter during thyroid hormone treatment. Molecular alterations were similar in patients with or without an event. No treatment-related adverse events were reported.

CONCLUSIONS

In patients with low-risk thyroid cancer undergoing thyroidectomy, a follow-up strategy that did not involve the use of radioiodine was noninferior to an ablation strategy with radioiodine regarding the occurrence of functional, structural, and biologic events at 3 years. (Funded by the French National Cancer Institute; ESTIMABL2 ClinicalTrials.gov number, NCT01837745.).

Adapted dietary inflammatory index and differentiated thyroid carcinoma risk in two French population-based case-control studies

PURPOSE

Thyroid cancer is the most common endocrine cancer and its etiology is still not well understood. The aim of the present study was to assess the association between an adapted dietary inflammatory index and differentiated thyroid cancer (DTC) risk in two population-based case-control studies (CATHY and YOUNG-THYR) conducted in France.

METHODS

These studies included a total of 1321 DTC cases and 1502 controls, for which an adapted dietary inflammatory index (ADII) was computed based on food frequency questionnaires in each study separately. The association between ADII and thyroid cancer risk was assessed using logistic regression models controlling for potential confounders.

RESULTS

Higher ADII scores, corresponding to a higher pro-inflammatory potential of the diet, were associated with higher DTC risk (odds ratio (OR) for 1 standard deviation (SD) increase: 1.09, 95% confidence interval (CI): 1.01, 1.18, P: 0.03). Associations were stronger in analyses restricted to women (OR for 1-SD increase: 1.14, 95% CI 1.04, 1.25, P: 0.005), as well as in women with lower education level, current smoking, or high body mass index.

CONCLUSION

Our study suggests that a pro-inflammatory diet is associated with an increased risk of DTC, especially when combined with other inflammatory conditions such as tobacco smoking or overweight. Our findings will help better understand the role of diet-induced inflammation in DTC etiology.

Multiethnic genome-wide association study of differentiated thyroid cancer in the EPITHYR consortium

Incidence of differentiated thyroid carcinoma (DTC) varies considerably between ethnic groups, with particularly high incidence rates in Pacific Islanders. DTC is one of the cancers with the highest familial risk suggesting a major role of genetic risk factors, but only few susceptibility loci were identified so far. In order to assess the contribution of known DTC susceptibility loci and to identify new ones, we conducted a multiethnic genome-wide association study (GWAS) in individuals of European ancestry and of Oceanian ancestry from Pacific Islands. Our study included 1554 cases/1973 controls of European ancestry and 301 cases/348 controls of Oceanian ancestry from seven population-based case-control studies participating to the EPITHYR consortium. All participants were genotyped using the OncoArray-500K Beadchip (Illumina). We confirmed the association with the known DTC susceptibility loci at 2q35, 8p12, 9q22.33 and 14q13.3 in the European ancestry population and suggested two novel signals at 1p31.3 and 16q23.2, which were associated with thyroid-stimulating hormone levels in previous GWAS. We additionally replicated an association with 5p15.33 reported previously in Chinese and European populations. Except at 1p31.3, all associations were in the same direction in the population of Oceanian ancestry. We also observed that the frequencies of risk alleles at 2q35, 5p15.33 and 16q23.2 were significantly higher in Oceanians than in Europeans. However, additional GWAS and epidemiological studies in Oceanian populations are needed to fully understand the highest incidence observed in these populations.

Role of DNA Repair Variants and Diagnostic Radiology Exams in Differentiated Thyroid Cancer Risk: A Pooled Analysis of Two Case-Control Studies

BACKGROUND

Given the increased use and diversity of diagnostic procedures, it is important to understand genetic susceptibility to radiation-induced thyroid cancer.

METHODS

On the basis of self-declared diagnostic radiology examination records in addition to existing literature, we estimated the radiation dose delivered to the thyroid gland from diagnostic procedures during childhood and adulthood in two case-control studies conducted in France. A total of 1,071 differentiated thyroid cancer (DTC) cases and 1,188 controls from the combined studies were genotyped using a custom-made Illumina OncoArray DNA chip. We focused our analysis on variants in genes involved in DNA damage response and repair pathways, representing a total of 5,817 SNPs in 571 genes. We estimated the OR per milli-Gray (OR/mGy) of the radiation dose delivered to the thyroid gland using conditional logistic regression. We then used an unconditional logistic regression model to assess the association between DNA repair gene variants and DTC risk. We performed a meta-analysis of the two studies.

RESULTS

The OR/mGy was 1.02 (95% confidence interval, 1.00-1.03). We found significant associations between DTC and rs7164173 in CHD2 (P = 5.79 × 10-5), rs6067822 in NFATc2 (P = 9.26 × 10-5), rs1059394 and rs699517 both in ENOSF1/THYS, rs12702628 in RPA3, and an interaction between rs7068306 in MGMT and thyroid radiation doses (P = 3.40 × 10-4).

CONCLUSIONS

Our results suggest a role for variants in CDH2, NFATc2, ENOSF1/THYS, RPA3, and MGMT in DTC risk.

IMPACT

CDH2, NFATc2, ENOSF1/THYS, and RPA3 have not previously been shown to be associated with DTC risk.

Gene network and biological pathways associated with susceptibility to differentiated thyroid carcinoma

Variants identified in earlier genome-wide association studies (GWAS) on differentiated thyroid carcinoma (DTC) explain about 10% of the overall estimated genetic contribution and could not provide complete insights into biological mechanisms involved in DTC susceptibility. Integrating systems biology information from model organisms, genome-wide expression data from tumor and matched normal tissue and GWAS data could help identifying DTC-associated genes, and pathways or functional networks in which they are involved. We performed data mining of GWAS data of the EPITHYR consortium (1551 cases and 1957 controls) using various pathways and protein-protein interaction (PPI) annotation databases and gene expression data from The Cancer Genome Atlas. We identified eight DTC-associated genes at known loci 2q35 (DIRC3), 8p12 (NRG1), 9q22 (FOXE1, TRMO, HEMGN, ANP32B, NANS) and 14q13 (MBIP). Using the EW_dmGWAS approach we found that gene networks related to glycogenolysis, glycogen metabolism, insulin metabolism and signal transduction pathways associated with muscle contraction were overrepresented with association signals (false discovery rate adjusted p-value < 0.05). Additionally, suggestive association of 21 KEGG and 75 REACTOME pathways with DTC indicate a link between DTC susceptibility and functions related to metabolism of cholesterol, amino sugar and nucleotide sugar metabolism, steroid biosynthesis, and downregulation of ERBB2 signaling pathways. Together, our results provide novel insights into biological mechanisms contributing to DTC risk.

Prognostic Factors and Survival Score for Patients With Anaplastic Thyroid Carcinoma: A Retrospective Study from a Regional Registry

BACKGROUND/AIM

Anaplastic thyroid carcinoma (ATC) is the least common but most lethal of thyroid cancer, despite various therapeutic options, with limited efficacy. In order to help therapeutic decision-making, the purpose of this study was to develop a new prognostic score providing survival estimates in patients with ATC.

PATIENTS AND METHODS

Based on a multivariate analysis of 149 retrospectively analyzed patients diagnosed with ATC from 1968 to 2017 at a referral center, a propensity score was developed. A model was generated providing survival probability at 6 months and median overall survival estimates.

RESULTS

The median survival was 96 days. The overall survival rate was 35% at 6 months, 20% at 1 year and 13% at 2 years. Stepwise Cox regression revealed that the most appropriate death prediction model included metastatic spread, tumor size and age class as explanatory variables. This model made it possible to define three categories of patients with different survival profiles.

CONCLUSION

Distant metastasis, age and primary tumor size are strong independent factors that affect prognosis in patients with ATC. Using these significant pretreatment factors, we developed a score to predict survival in these patients with poor prognosis.

Fine-mapping of two differentiated thyroid carcinoma susceptibility loci at 2q35 and 8p12 in Europeans, Melanesians and Polynesians

Differentiated thyroid carcinoma (DTC) incidence is characterized by wide ethnic and geographic variations, with high incidence rates observed in Oceanian populations. Genome-wide association studies (GWAS) identified mainly four DTC susceptibility loci at 9q22.33, 14q13.3, 2q35 and 8p12. Here we performed fine-mapping of the 2q35 and 8p12 loci in the population of the EPITHYR consortium that includes Europeans, Melanesians and Polynesians to identify likely causal variants for DTC risk. We conducted a colocalization analysis using eQTLs data to determine the SNPs with the highest probability of causality. At 2q35, we highlighted rs16857609 located in DIRC3. This SNP has a high probability of causality in the three populations, and a significant association in Europeans (OR = 1.4, p = 1.9 x 10-10). It is also associated with expression of DIRC3 and of the nearby gene IGFBP5 in thyroid tumour cells. At 8p12, we identified rs7844425 which was significantly associated with DTC in Europeans (OR = 1.32, p = 7.6 x 10-8) and rs2439304, which was highlighted by the colocalization analysis but only moderately associated with DTC in our dataset (OR = 1.2, p = 0.001). These SNPs are linked to the expression of NRG1 in thyroid tissue. Hence, our study identified novel variants at 2q35 and 8p12 to be prioritized for further functional studies.

Progression of incidence and estimate of net survival from papillary thyroid cancers diagnosed between 2008 and 2016 in France

BACKGROUND

After several decades of increasing incidence of papillary thyroid cancer (PTC), a change in this trend has been recently observed, particularly in the United States. This is attributed to the impact of new guidelines for the management of thyroid disease. The objective of this study was to describe the recent situation in France in terms of incidence and survival, taking account of tumor size.

METHODS

Data from the FRANCIM network cancer registries, covering around 25% of the French metropolitan population, were analyzed. Distribution according to tumor size was determined in terms of frequency, trends in incidence and spatial distribution for the period 2008-2016. Analysis of net survival considered gender, age and tumor size.

RESULTS

Cancers of size≤5mm were predominant in patients diagnosed between 55 and 74 years of age. Incidence of≤5mm tumors in women and of 5-10mm tumors in men began declining in the early 2010s. Incidence of 10-20mm and 20-40mm tumors in men increased significantly throughout the period 2008-2016. For both men and women, the incidence of the largest tumors (>40mm) also increased, but not significantly. The spatial distribution of incidence showed great heterogeneity. Net survival was generally high, although decreasing with age and tumor size.

CONCLUSION

The recent epidemiological situation in France is consistent with the hypothesis of recent progress in medical management of thyroid pathologies. Variations in incidence should be monitored for both small (<10mm) and larger tumors, and notably>40mm tumors. Net survival is generally high, although decreasing with age and tumor size.

Role of GSTM1 and GSTT1 genotypes in differentiated thyroid cancer and interaction with lifestyle factors: Results from case-control studies in France and New Caledonia

Background

GSTM1 and GSTT1 are involved in detoxification of xenobiotics, products of oxidative stress and in steroid hormones metabolism. We investigated whether GSTM1 and GSTT1 gene deletion was associated with DTC risk and explored interaction with non-genetic risk factors of DTC.

Methods

The study included 661 DTC cases and 736 controls from two case-control studies conducted in France and New Caledonia. Odds ratios (OR) and their confidence interval (CI) for DTC associated with GST genotypes, alcohol drinking, tobacco smoking, body mass index and hormonal factors were calculated using logistic regression models.

Results

Results are presented for Europeans and Melanesians combined, as no heterogeneity between groups was detected. We found that DTC risk increased with obesity and decrease with alcohol drinking. After stratification by gene deletion status, the OR for obesity was 5.75, (95%CI 2.25–14.7) among individuals with GSTT1 and GSTM1-deleted genotype, and 1.26, (95%CI 0.89–1.77) in carriers of both genes (p-interaction = 0.02). The OR for drinking ≥1 glass/week was 0.33 (95%CI 0.15–0.74) in GSTT1-null individuals while it was 1.01 (95%CI 0.67–1.52) in non-null carriers of the gene (p-interaction = 0.01). No interaction between GST genotypes and other non-genetic risk factors was detected.

Conclusion

GSTM1 and GSTT1 genotypes may modulate the DTC risk associated with BMI and alcohol consumption.

Long-term progression of non-invasive follicular thyroid neoplasm with papillary-like nuclear features: A single-center retrospective study of the French Marne-Ardennes thyroid cancer registry

CONTEXT

Non-invasive forms of encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) were reclassified as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) in order to reduce overtreatment. A few studies showed neck lymphadenopathy at diagnosis, or even distant metastasis in patients with NIFTP.

OBJECTIVE

Our aim was to report the frequency, clinical features and long-term progression of histologically confirmed NIFTP, using data from the French Marne-Ardennes thyroid cancer registry, and to compare findings against FVPTC.

METHODS

This was a retrospective study on data for follicular variant of PTC (FVPTC) diagnosed between 1975 and 2015 obtained from the specialized Marne-Ardennes thyroid cancer registry. Pathology reports were used to select appropriate cases from a large series, and FVPTC specimens were reviewed by endocrine pathologists. Strict diagnostic criteria were used for reclassification as NIFTP.

RESULTS

In total, 115 cases were reviewed histologically out of 383 cases of FVPTC. Sixty-five met all criteria for NIFTP and were consequently reclassified. Incidence of NIFTP was 16.9% of cases of FVPTC. Fifty patients were women (76.9%); median age was 47 years. Mean NIFTP size was 2.6 cm. There were no significant differences in age, gender or tumor size between NIFTP and FVPTC. Fifty patients underwent total thyroidectomy and 15 lobectomy. There were no lymph node metastases at diagnosis, and none of the patients (N=17) who underwent central and/or lateral neck dissection had positive findings on microscopic examination. 46 patients (70.8%) received radioiodine (RAI). Patients were followed up for 1.9-27.3 years (median 14.6 years) after initial treatment. All patients remained in complete remission during follow-up.

CONCLUSION

Consistently with previous studies, our results showed the indolent course of NIFTP and that risk of recurrence after complete resection is very low (zero in our cohort), even when size is ≥4cm and in absence of adjuvant RAI treatment. Prospective studies are needed to confirm those results.

Three Consecutive Pregnancies in a Patient with Chronic Autoimmune Thyroid Disease Associated with Hypothyroidism and Extremely High Levels of Anti-Thyrotropin Receptor Antibodies

Background: Thyroid-stimulating hormone (TSH) receptor (TSHR) antibodies (TRAb) can be present in chronic autoimmune thyroiditis. Transplacental TRAb transfer can lead to fetal thyroid dysfunction and serious complications. Patient Findings: We report the case of a woman with autoimmune hypothyroidism and extremely high TRAb levels, with blocking and stimulating activities (biological activities characterized with Chinese hamster ovary cells expressing TSHR). At week 22 of her first pregnancy, sonography detected fetal growth retardation and cardiac abnormalities (extreme tachycardia, right ventricular dilatation, pericardial effusion). The mother's TRAb level, assayed later, was 4030 IU/L (n < 10). Delivered via caesarean section gestational week 30, the newborn girl had several malformations, signs of malnutrition, goiter and hyperthyroidism associated with elevated TRAb (1200 IU/L). The newborn died 26 days after delivery. Faced with persistently high TRAb levels and a desire to become pregnant again, the woman was treated with three consecutive 740-MBq activities of iodine-131, which resulted in a decrease in TRAb to 640 IU/L. The patient had two subsequent pregnancies 16 and 72 months after the radioiodine administration. During the close follow-ups, fetal development was normal, and initial TRAb levels during the two pregnancies were 680 and 260 IU/L, respectively, which initially decreased but then increased in late pregnancy. In both cases, labor was induced at 34 weeks. The newborns, mildly hyperthyroid at birth, required carbimazole treatment at days 5 and 2, respectively. The mild hyperthyroidism despite high TRAb levels was likely due to the concomitant presence of stimulating and blocking TRAb. The two girls, now aged 12 and 8 years, are in good health. The mother has no detectable thyroid gland tissue and is euthyroid on levothyroxine (175 μg/d). Her TRAb level gradually decreased to 136 IU/L. Summary and Conclusions: This remarkable case illustrates the severe consequences of untreated fetal hyperthyroidism and the need to assay and follow-up TRAb levels in women of reproductive age with autoimmune thyroiditis.

Recombinant Thyrotropin vs Levothyroxine Withdrawal in 131I Therapy of N1 Thyroid Cancer: A Large Matched Cohort Study (ThyrNod)

CONTEXT

Recombinant human thyrotropin (rhTSH) has been shown to be an effective stimulation method for radioactive iodine (RAI) therapy in differentiated thyroid cancer, including in those with nodal metastases (N1 DTC).

OBJECTIVES

To demonstrate the noninferiority of rhTSH vs thyroid hormone withdrawal (THW) in preparation to RAI regarding disease status at the first evaluation in the real-life setting in patients with N1 DTC.

DESIGN

This was a French multicenter retrospective study. Groups were matched according to age (<45/≥45 years), number of N1 nodes (≤5/>5 lymph nodes), and stage (pT1-T2/pT3).

RESULTS

The cohort consisted of 404 patients pT1-T3/N1/M0 DTC treated with rhTSH (n = 205) or THW (n = 199). Pathological characteristics and initially administrated RAI activities (3.27 ± 1.00 GBq) were similar between the two groups. At first evaluation (6 to 18 months post-RAI), disease-free status was defined by thyroglobulin levels below threshold and a normal ultrasound. Disease-free rate was not inferior in the rhTSH group (75.1%) compared with the THW group (71.9%). The observed difference between the success rates was 3.3% (-6.6 to 13.0); rhTSH was therefore considered noninferior to THW because the upper limit of this interval was <15%. At the last evaluation (29.7 ± 20.7 months for rhTSH; 36.7 ± 23.8 months for THW), 83.5% (rhTSH) and 81.5% (THW) of patients achieved a complete response. This result was not influenced by any of the known prognostic factors.

CONCLUSIONS

A preparation for initial RAI treatment with rhTSH was noninferior to that with THW in our series of pT1-T3/N1/M0-DTC on disease-free status outcomes at the first evaluation and after 3 years.

Outcome after ablation in patients with low-risk thyroid cancer (ESTIMABL1): 5-year follow-up results of a randomised, phase 3, equivalence trial

BACKGROUND

In ESTIMABL1, a randomised phase 3 trial of radioactive iodine (131I) administration after complete surgical resection in patients with low-risk thyroid cancer, 92% of patients had complete thyroid ablation at 6-10 months, defined as a recombinant human thyroid-stimulating hormone (rhTSH)-stimulated serum thyroglobulin concentration of 1 ng/mL or less and normal findings on neck ultrasonography. Equivalence was shown between low-activity (1·1 GBq) and high-activity (3·7 GBq) radioactive iodine and also between the use of rhTSH injections and thyroid hormone withdrawal. Here, we report outcomes after 5 years of follow-up.

METHODS

This multicentre, randomised, open-label, equivalence trial was done at 24 centres in France. Between March 28, 2007, and Feb 25, 2010, we randomly assigned (1:1:1:1) adults with low-risk differentiated thyroid carcinoma who had undergone total thyroidectomy to one of four strategies, each combining one of two methods of thyrotropin stimulation (rhTSH or thyroid hormone withdrawal) and one of two radioactive iodine activities (1·1 GBq or 3·7 GBq). Randomisation was by computer-generated sequence, with variable block size. Follow-up consisted of a yearly serum thyroglobulin measurement on levothyroxine treatment. Measurement of rhTSH-stimulated thyroglobulin and neck ultrasonography were done at the discretion of the treating physician. No evidence of disease was defined as serum thyroglobulin of 1 ng/mL or less on levothyroxine treatment and normal results on neck ultrasonography, when performed. This study was registered with ClinicalTrials.gov, number NCT00435851.

FINDINGS

726 patients (97% of the 752 patients originally randomised) were followed up. At a median follow-up since randomisation of 5·4 years (range 0·5-9·2), 715 (98%) had no evidence of disease. The other 11 had either structural disease (n=4), raised serum thyroglobulin concentration (n=5), or indeterminate findings on neck ultrasonography (n=2). At ablation, six of these patients had received 1·1 GBq radioactive iodine (five after rhTSH and one after withdrawal) and five had received 3·7 GBq (two after rhTSH and three after withdrawal). TSH-stimulated (either after rhTSH injections or thyroid hormone withdrawal according to the treatment group) thyroglobulin concentration measured at the time of ablation was prognostic for structural disease status at ablation, ablation status at 6-10 months, and the final outcome.

INTERPRETATION

Our findings suggest that disease recurrence was not related to the strategy used for ablation. These data validate the use of 1·1 GBq radioactive iodine after rhTSH for postoperative ablation in patients with low-risk thyroid cancer.

FUNDING

French National Cancer Institute (INCa), French Ministry of Health, and Sanofi Genzyme.

Modeling therapeutic response to radioiodine in metastatic thyroid cancer: a proof-of-concept study for individualized medicine

Purpose

Radioiodine therapy (RAI) has traditionally been used as treatment for metastatic thyroid cancer, based on its ability to concentrate iodine. Propositions to maximize tumor response with minimizing toxicity, must recognize the infinite possibilities of empirical tests. Therefore, an approach of this study was to build a mathematical model describing tumor growth with the kinetics of thyroglobulin (Tg) concentrations over time, following RAI for metastatic thyroid cancer.

Experimental Design

Data from 50 patients with metastatic papillary thyroid carcinoma treated within eight French institutions, followed over 3 years after initial RAI treatments, were included in the model. A semi-mechanistic mathematical model that describes the tumor growth under RAI treatment was designed.

Results

Our model was able to separate patients who responded to RAI from those who did not, concordant with the physicians' determination of therapeutic response. The estimated tumor doubling-time (Td was found to be the most informative parameter for the distinction between responders and non-responders. The model was also able to reclassify particular patients in early treatment stages.

Conclusions

The results of the model present classification criteria that could indicate whether patients will respond or not to RAI treatment, and provide the opportunity to perform personalized management plans.

Dietary habits during the 2 months following the Chernobyl accident and differentiated thyroid cancer risk in a population-based case-control study

BACKGROUND

The Chernobyl nuclear power plant accident occurred in Ukraine on April 26th 1986. In France, the radioactive fallout and thyroid radiation doses were much lower than in highly contaminated areas. However, a number of risk projections have suggested that a small excess in differentiated thyroid cancer (DTC) might occur in eastern France due to this low-level fallout. In order to investigate this potential impact, a case-control study on DTC risk factors was started in 2005, focusing on cases who were less than 15 years old at the time of the Chernobyl accident. Here, we aim to evaluate the relationship between some specific reports of potentially contaminated food between April and June 1986 - in particular fresh dairy products and leafy vegetables - and DTC risk.

METHODS

After excluding subjects who were not born before the Chernobyl accident, the study included 747 cases of DTC matched with 815 controls. Odds ratios were calculated using conditional logistic regression models and were reported for all participants, for women only, for papillary cancer only, and excluding microcarcinomas.

RESULTS

The DTC risk was slightly higher for participants who had consumed locally produced leafy vegetables. However, this association was not stronger in the more contaminated areas than in the others. Conversely, the reported consumption of fresh dairy products was not statistically associated with DTC risk.

CONCLUSION

Because the increase in DTC risk associated with a higher consumption of locally produced vegetables was not more important in the most contaminated areas, our study lacked power to provide evidence for a strong association between consumption of potentially contaminated food and DTC risk.

Are dietary reports in a case-control study on thyroid cancer biased by risk perception of Chernobyl fallout?

BACKGROUND

In retrospective case-control studies performed following nuclear tests or nuclear accidents, individual thyroid radiation dose reconstructions are based on fallout and meteorological data from the residential area, demographic characteristics, and lifestyle as well as dietary information. Collecting the latter is a controversial step, as dietary declarations may be affected by the subjects' beliefs about their risk behavior. This report analyses the potential for such bias in a case-control study performed in eastern France.

METHODS

The study included 765 cases of differentiated thyroid carcinoma matched with 831 controls. Risk perceptions and beliefs of cases and controls were compared using Chi² tests and differences in dietary reports were analyzed using a two-way ANOVA.

RESULTS

In general, atmospheric pollution and living near a nuclear power plant were the two major risks that may influence thyroid cancer occurrence cited by cases and controls. When focusing in particular on the consequences of the Chernobyl accident, cases were more likely to think that the consequences were responsible for thyroid cancer occurrence than controls. Vegetable consumption during the two months after the Chernobyl accident was correlated with the status of subjects, but not to their beliefs. Conversely, consumption of fresh dairy products was not correlated with the status or beliefs of subjects.

CONCLUSION

We found no evidence of systematic bias in dietary reports according to the status or beliefs held by subjects about the link between thyroid cancer occurrence and Chernobyl fallout. As such, these dietary reports may be used in further studies involving individual dosimetric reconstructions.

Overdiagnosis of thyroid cancer in the Marne and Ardennes Departments of France from 1975 to 2014

OBJECTIVES

Incidence of thyroid cancer has increased considerably in France in recent years, but the mortality rate has declined only slightly. Part of this increased incidence could be attributable to overdiagnosis. We aimed to estimate the contribution of overdiagnosis to the incidence of papillary thyroid cancer.

MATERIAL AND METHODS

Incidence rates were calculated based on data from the specialised Marnes-Ardennes thyroid cancer registry, for cancers diagnosed between 1975 and 2014, by age category and by five-year period. The population was divided into two groups according to pTNM classification at diagnosis (i.e. localised or invasive). Overdiagnosis was defined as the difference in incidence rates between the invasive cancer and localised cancer groups. This rate was then divided by the incidence rate in the localised cancer group for the most recent period (2010-2014) to obtain the proportion of cancers attributable to overdiagnosis.

RESULTS

In total, 2008 patients were included. The proportion of incidence attributable to overdiagnosis for the period 2010-2014 was estimated at 7 and 62% in men and women aged < 50 years respectively, and at 65 and 73% respectively in men and women aged ≥ 50 years.

CONCLUSION

We observed a high proportion of cancers attributable to overdiagnosis. This finding raises the issue of patient management, with the risk of overtreatment, and the repercussions on quality of life for patients diagnosed with cancer.

Recreational Physical Activity and Differentiated Thyroid Cancer Risk: A Pooled Analysis of Two Case-Control Studies

PURPOSE

Physical activity has been hypothesized to influence cancer occurrence through several mechanisms. To date, its relation with thyroid cancer risk has been examined in relatively few studies. We pooled 2 case-control studies conducted in Cuba and Eastern France to assess the relationship between self-reported practice of recreational physical activity since childhood and thyroid cancer risk.

METHODS

This pooled study included 1,008 cases of differentiated thyroid cancer (DTC) matched with 1,088 controls (age range 9-35 and 17-60 years in the French and Cuban studies, respectively). Risk factors associated with the practice of recreational physical activity were estimated using OR and 95% CI. Logistic regressions were stratified by age class, country, and gender and were adjusted for ethnic group, level of education, number of pregnancies for women, height, BMI, and smoking status.

RESULTS

Overall, the risk of thyroid cancer was slightly reduced among subjects who reported recreational physical activity (OR = 0.8; 95% CI 0.5-1.0). The weekly frequency (i.e. h/week) seems to be more relevant than the duration (years).

CONCLUSION

Long-term recreational physical activity, practiced since childhood, may reduce the DTC risk. However, the mechanisms whereby the DTC risk decreases are not yet entirely clear.

Quality of life, clinical outcomes and safety of early prophylactic levothyroxine administration in patients with Graves' hyperthyroidism undergoing radioiodine therapy: a randomized controlled study

OBJECTIVE

While radioiodine therapy is commonly used for treating Graves' disease, a prolonged and clinical hypothyroidism may result in disabling symptoms leading to deterioration of quality of life (QoL) of patients. Introducing levothyroxine (LT4) treatment in the early post-therapeutic period may be an interesting approach to limit this phenomenon.

METHODS

A multicenter, prospective, open-label randomized controlled trial enrolled 94 patients with Graves' hyperthyroidism randomly assigned to the experimental group (n=46) (group A: early prophylactic LT4 treatment) or the control group (n=48) (group B: standard follow-up). The primary endpoint was the 6-month QoL. The secondary endpoints were other QoL scores such as Graves' ophthalmopathy (GO) outcomes, thyroid function tests and safety.

RESULTS

The primary endpoint at 6 months was achieved: the mental composite score (MCS) of Short Form 36 (SF-36) was significantly higher in group A compared to group B (P=0.009). Four other dimension scores of the SF-36 and four dimension scores of the thyroid-specific patient-reported outcome (ThyPRO) significantly differed between the two groups, indicating better QoL in group A. After adjustment for variables, the early LT4 administration strategy was found as an independent factor for only two scores of SF-36: the MCS and the general health (GH) score. There were no differences in GO, final thyroid status and changes in the anti-TSH receptor antibodies (TRAbs) levels between the two groups. No adverse cardiovascular event was reported.

CONCLUSION

Early LT4 administration post-radioactive iodine (RAI) could represent a safe potential benefit for patients with regard to QoL. The optimal strategy taking into account administered RAI activities and LT4 treatment dosage and timing remains to be determined.

Fine-mapping of two differentiated thyroid carcinoma susceptibility loci at 9q22.33 and 14q13.3 detects novel candidate functional SNPs in Europeans from metropolitan France and Melanesians from New Caledonia

Incidence of differentiated thyroid carcinoma varies considerably between countries and ethnic groups, with particularly high incidence rates in Melanesians of New Caledonia. Differentiated thyroid cancer (DTC) has a familial relative risk higher than other cancers, highlighting the contribution of inherited factors to the disease. Recently, genome-wide association studies (GWAS) identified several DTC susceptibility loci. The most robust associations were reported at loci 9q22 (rs965513 and rs1867277) and 14q13 (rs944289 and rs116909734). In this study, we performed a fine-mapping study of the two gene regions among Europeans and Melanesians from Metropolitan France and New Caledonia. We examined 81 single nucleotide polymorphisms (SNPs) at 9q22 and 561 SNPs at 14q13 in Europeans (625 cases/776 controls) and in Melanesians (244 cases/189 controls). The association with the four SNPs previously identified in GWAS was replicated in Europeans while only rs944289 was replicated in Melanesians. Among Europeans, we found that the two SNPs previously reported at 9q22 were not independently associated to DTC and that rs965513 was the predominant signal; at 14q13, we showed that the haplotype rs944289[C]-rs116909374[C]-rs999460[T] was significantly associated with DTC risk and that the association with rs116909374 differed by smoking status (p-interaction = 0.03). Among Melanesians, a new independent signal was observed at 14q13 for rs1755774 which is strongly correlated to rs2787423; this latter is potentially a functional variant. Significant interactions with parity (p < 0.05) and body mass index were observed for rs1755774 and rs2787423. This study contributed to a better characterization of the DTC loci 9q22 and 14q13 in Europeans and in Melanesians and has identified novel variants to be prioritized for further functional studies.

Prophylactic neck dissection for low-risk differentiated thyroid cancers: Risk-benefit analysis

BACKGROUND

The benefit of neck dissection is the subject of debate in differentiated thyroid cancer (DTC). We analyze the risk-benefit of neck dissection for low-risk DTC without detectable lymph nodes.

METHODS

We conducted a retrospective study from 1983 to 2003; which included 295 patients without detectable lymph nodes who were treated by thyroidectomy with (C+) or without (C-) neck dissection. All patients had iodine131 therapy. We compared the frequency of remission, disease progression, and permanent complications between groups.

RESULTS

Two hundred twelve patients comprised the C+ group, and 83 patients the C- group. Respectively for C+ versus C-, remission rates were 92% versus 89.2% (p = .40), and progressive disease observed was 3.3% versus 7.2% (p = .10). Permanent hypoparathyroidism occurred in 15.1% in C+ versus 3.6% in C- (p = .006).

CONCLUSION

The risk-benefit analysis of neck dissection in patients with low-risk DTC shows no benefit in terms of complete remission or occurrence of progression. However, risk of complications seems to be higher in patients with neck dissection. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1091-1096, 2016.

Survival in patients with primary liver cancer, gallbladder and extrahepatic biliary tract cancer and pancreatic cancer in Europe 1999-2007: Results of EUROCARE-5

BACKGROUND

The EUROCARE study collects and analyses survival data from population-based cancer registries (CRs) in Europe in order to provide data on between-country differences in survival and time trends in survival.

METHODS

This study analyses data on liver cancer, gallbladder and extrahepatic biliary tract cancers ("biliary tract cancers"), and pancreatic cancer diagnosed in 2000-2007 from 88 CRs in 29 countries. Relative survival (RS) was estimated overall, by region, sex, age and period of diagnosis using the complete approach. Time trends in 5-year RS over 1999-2007 were also analysed using the period approach.

RESULTS

The prognosis of the studied cancers was poor. Age-standardised 5-year RS was 12% for liver cancer, 17% for biliary tract cancers and 7% for pancreatic cancer. There were some between-country differences in survival. In general, RS was low in Eastern Europe and high in Central and Southern Europe. For all sites, 5-year RS was similar in men and women and decreased with advancing age. No substantial changes in survival were reported for pancreatic cancer over the period 1999-2007. On average, there was a crude increase in 5-year RS of 3 percentage points between the periods 1999-2001 and 2005-2007 for liver cancer and biliary tract cancers.

CONCLUSIONS

The major changes in imaging techniques over the study period for the diagnosis of the three studied cancers did not result in an improvement in the prognosis of these cancers. In the near future, new innovative treatments might be the best way to improve the prognosis in these cancers.

Quality of Life and Cost-Effectiveness Assessment of Radioiodine Ablation Strategies in Patients With Thyroid Cancer: Results From the Randomized Phase III ESTIMABL Trial

Purpose

In the ESTIMABL phase III trial, the thyroid ablation rate was equivalent for the two thyroid-stimulating hormone (TSH) stimulation methods (thyroid hormone withdrawal [THW] and recombinant human TSH [rhTSH]) and the two iodine-131 (131I) activities (1.1 or 3.7 GBq). The objectives of this article were to present health-related quality-of-life (HRQoL) results and a cost-effectiveness evaluation performed alongside this trial.

Patients and Methods

HRQoL and utility were longitudinally assessed, from random assignment to the follow-up visit at 8 ± 2 months for the 752 patients with thyroid cancer, using the Short Form-36 and the EuroQoL-5D questionnaires, respectively. A cost-effectiveness analysis was performed from the societal perspective in the French context. Resource use (hospitalization for 131I administration, rhTSH, sick leaves, and transportation) was collected prospectively. We used the net monetary benefit approach and computed cost-effectiveness acceptability curves for both TSH stimulation methods and 131I activities. Sensitivity analyses of the costs of rhTSH were performed.

Results

At 131I administration, THW caused a clinically significant deterioration of HRQoL, whereas HRQoL remained stable with rhTSH. This deterioration was transient with no difference 3 months later. rhTSH was more effective than THW in terms of quality-adjusted life-years (QALYs; +0.013 QALY/patient) but more expensive (+€474/patient). The probability that rhTSH would be cost effective at a €50,000/QALY threshold was 47% in France. The use of 1.1 GBq of 131I instead of 3.7 GBq reduced per-patient costs by €955 (US$1,018) but with slightly decreased efficacy (−0.007 QALY/patient).

Conclusion

rhTSH avoids the transient THW-induced deterioration of HRQoL but is unlikely to be cost effective at its current price.

Anthropometric Risk Factors for Differentiated Thyroid Cancer in Young Men and Women From Eastern France: A Case-Control Study

The incidence of thyroid cancer has risen over the past decade, along with a rise in obesity. We studied the role of anthropometric risk factors for differentiated thyroid cancer at the time of diagnosis and at age 20 years in a case-control study conducted in eastern France between 2005 and 2010. The study included 761 adults diagnosed with differentiated thyroid cancer before 35 years of age between 2002 and 2006. They were matched with 825 controls from the general population. Odds ratios were calculated using conditional logistic regression models and were reported for all participants, those with papillary cancer only, and women only. The risk of thyroid cancer was higher for participants with a high body surface area (BSA), great height, or excess weight and for women with a high body fat percentage. Conversely, no significant association was found between body mass index and the risk of thyroid cancer. In the present study, we provide further evidence of the role of BSA and excess weight in the risk of thyroid cancer. These epidemiologic observations should be confirmed by further exploration of the biological mechanisms responsible for the associations of obesity and BSA with thyroid cancer.

Recent trends in incidence, geographical distribution, and survival of papillary thyroid cancer in France

BACKGROUND

Over the past few decades, the incidence of thyroid cancer has dramatically increased in many countries. This increase was mainly seen in papillary cancer. The role of diagnostic practices and the effects of other risk factors were suggested to explain this increase. We provide a descriptive analysis in terms of changes in incidence, geographical distribution, and survival to check the relevance of assumptions about the increase.

METHODS

A detailed analysis of changes in incidence recorded in French cancer registries between 1982 and 2010 was performed taking into account age, period, and birth cohort. The geographical distribution of the incidence in the 2006-2010 period was estimated from the standardized incidence ratios. The net survival was estimated to evaluate the effects of sex, age, and period of diagnosis in patients diagnosed between 1989 and 2004 and followed-up until 2013.

RESULTS

The incidence of papillary cancer has increased sharply over the 1982-2010 period; the average annual rate of increase was 7.8% in men and 7.2% in women. The increase has slowed in the recent period in people aged less than 50 at the time of diagnosis. It has also slowed in the cohorts born 1945 and after. There was a strong geographic disparity in incidence between areas covered by cancer registries. Finally, the net survival was very high; the 10-year net survival was 96% and improved progressively from 82% in patients diagnosed between 1989 and 1993 to 95% in those diagnosed between 1999 and 2004.

CONCLUSION

The increased incidence results most probably from the effect of medical practice, although other risk factors seem also involved, but to a lesser extent. The increase seems to have slowed down in the recent years, especially in the youngest age groups. This observation suggests a recent trend towards saturation of the effects of medical practices in post-1945 cohorts associated with an effect of the gradual dissemination of the recommendations relative to the management of thyroid nodules.

Vandetanib for the treatment of advanced medullary thyroid cancer outside a clinical trial: results from a French cohort

BACKGROUND

A randomized phase III trial demonstrated that vandetanib treatment is effective in patients with metastatic medullary thyroid cancer (MTC), leading to regulatory approval, but its use may be associated with toxicities that require specific monitoring and management. The objective of the present study performed in France was to describe the toxicity profile and efficacy of vandetanib treatment when given outside any trial.

METHODS

Sixty-eight patients were treated with vandetanib in the frame of a temporary use authorization (ATU) in France from August 2010 to February 2012, when the drug was available on request for patients with locally advanced or metastatic MTC. Patients were registered by the French health authorities, and characteristics, treatment parameters, toxicity profile, and efficacy were retrospectively reviewed. Eight patients were excluded from the analysis because vandetanib treatment was not administered (n=3), had been given in a trial before ATU (n=3), or was given for a non-MTC cancer (n=2).

RESULTS

Data from the 60 MTC patients were analyzed. Mean age was 58 years (range 11-83 years), 39 patients were male, and six had hereditary MTC. Fifty-six (93%) had metastatic disease in the mediastinum (82%), bones (65%), liver (53%), or lung (53%), and four had only locally advanced disease. At the time of study evaluation, with a median follow-up of 20 months and a median duration of treatment of 9.7 months (range 0.3-36 months), 15 patients were continuing vandetanib treatment (range 18-36 months). Median progression-free survival was 16.1 months. Twenty-five patients discontinued treatment for disease progression (range 0.3-29 months). Best tumor response was a complete response in one patient, a partial response in 12 (20%), stable disease in 33 (55%), and progression in seven patients (12%). All patients had at least one adverse event (AE) during treatment. The main AEs were skin toxicity, diarrhea, and asthenia. Sixteen patients (27%) discontinued treatment for toxicity, and one patient died from vandetanib-induced cardiac toxicity.

CONCLUSIONS

Vandetanib is an effective option for patients with advanced MTC. AEs should be monitored carefully and should be minimized by educating both patients and care providers and by applying symptomatic treatment and dose reduction.

Menstrual and reproductive factors in the risk of differentiated thyroid carcinoma in young women in France: a population-based case-control study

The incidence of thyroid cancer has increased in eastern Europe since the Chernobyl nuclear power plant accident. Although the radioactive fallout was much less severe and the thyroid radiation dose was much lower in France, a case-control study was initiated in eastern France. The present study included 633 young women who were diagnosed with differentiated thyroid cancer before 35 years of age between 2002 and 2006 and matched with 677 controls. Face-to-face interviews were conducted from 2005 to 2010. Odds ratios were calculated using conditional logistic regressions and were reported in the total group and by histopathological type of cancer ("only papillary" and "excluding microcarcinomas"). The risk of thyroid cancer was higher in women who had a higher number of pregnancies, used a lactation suppressant, or had early menarche. Conversely, breastfeeding, oral contraceptive use, and late age at first pregnancy were associated with a lower risk of thyroid cancer. No association was observed between thyroid cancer and having irregular menstrual cycle, undergoing treatment for menstrual cycle regularity shortly after menarche, having a cessation of menstruation, use of another contraceptive, history of miscarriage or abortion for the first pregnancy, or having had gestational diabetes. This study confirms the role of hormonal and reproductive factors in thyroid cancer, and our results support the fact that exposure to estrogens increases thyroid cancer risk.

Strategies of radioiodine ablation in patients with low-risk thyroid cancer

BACKGROUND

It is not clear whether the administration of radioiodine provides any benefit to patients with low-risk thyroid cancer after a complete surgical resection. The administration of the smallest possible amount of radioiodine would improve care.

METHODS

In our randomized, phase 3 trial, we compared two thyrotropin-stimulation methods (thyroid hormone withdrawal and use of recombinant human thyrotropin) and two radioiodine ((131)I) doses (i.e., administered activities) (1.1 GBq and 3.7 GBq) in a 2-by-2 design. Inclusion criteria were an age of 18 years or older; total thyroidectomy for differentiated thyroid carcinoma; tumor-node-metastasis (TNM) stage, ascertained on pathological examination (p) of a surgical specimen, of pT1 (with tumor diameter ≤1 cm) and N1 or Nx, pT1 (with tumor diameter >1 to 2 cm) and any N stage, or pT2N0; absence of distant metastasis; and no iodine contamination. Thyroid ablation was assessed 8 months after radioiodine administration by neck ultrasonography and measurement of recombinant human thyrotropin-stimulated thyroglobulin. Comparisons were based on an equivalence framework.

RESULTS

There were 752 patients enrolled between 2007 and 2010; 92% had papillary cancer. There were no unexpected serious adverse events. In the 684 patients with data that could be evaluated, ultrasonography of the neck was normal in 652 (95%), and the stimulated thyroglobulin level was 1.0 ng per milliliter or less in 621 of the 652 patients (95%) without detectable thyroglobulin antibodies. Thyroid ablation was complete in 631 of the 684 patients (92%). The ablation rate was equivalent between the (131)I doses and between the thyrotropin-stimulation methods.

CONCLUSIONS

The use of recombinant human thyrotropin and low-dose (1.1 GBq) postoperative radioiodine ablation may be sufficient for the management of low-risk thyroid cancer. (Funded by the French National Cancer Institute [INCa] and the French Ministry of Health; ClinicalTrials.gov number, NCT00435851; INCa number, RECF0447.).

Impact on overall survival of radioactive iodine in low-risk differentiated thyroid cancer patients

CONTEXT

American Thyroid Association and European Thyroid Association guidelines cannot recommend for or against radioactive iodine (RAI) ablation after surgery in low-risk differentiated thyroid cancer (DTC) patients.

OBJECTIVES

The objective of the study was to assess the survival benefit of RAI for these patients.

DESIGN

We identified 1298 DTC patients at low risk treated between 1975 and 2005. Logistic regressions were used to identify variables associated to RAI and to calculate the propensity score to receive RAI after surgery. We compared overall survival (OS) and disease-free survival (DFS) according to RAI with the log-rank tests and univariate and multivariate Cox analyses. Analyses stratified on propensity score were also performed.

RESULTS

Median follow-up was 10.3 yr. Nine hundred eleven patients received RAI after surgery vs. 387 patients without RAI after surgery. Using univariate analysis, 10-yr OS was found to be 95.8% in patients without RAI after surgery vs. 94.6% in RAI after surgery (P = 0.006), and 10-yr DFS was found to be 93.1% vs. 88.7% (P = 0.001). All clinical factors except sex were significantly associated with RAI. Using multivariate Cox analyses, RAI was neither significantly nor independently associated with OS (P = 0.243) and DFS (P = 0.2659). After stratification on propensity score, Cox univariate analyses showed that OS did not differ according to RAI (P = 0.3524), with a hazard ratio for RAI of 0.75 (95% confidence interval 0.40-1.38). Similarly, DFS did not differ (P = 0.48) with a stratified univariate hazard ratio of 1.11 (95% confidence interval 0.73-1.70).

CONCLUSION

With a long-term follow-up of 10.3 yr, we failed to prove any survival benefit of RAI after surgery in a large cohort of low-risk DTC patients.

Long-term follow-up of patients with papillary and follicular thyroid cancer: a prospective study on 715 patients

PURPOSE

This prospective study evaluated the recurrence rate in 715 patients with differentiated thyroid cancer who had no evidence of persistent disease after total thyroidectomy and lymph node dissection in 94% of them followed up by radioiodine ablation (30-100 mCi) and assessed the predictive value of the initial thyroglobulin (Tg) levels for detecting recurrence, both during levothyroxine (LT4) treatment and after TSH stimulation.

PATIENTS AND METHODS

Patients had Tg determinations performed at 3 months on LT4 treatment (Tg1) and at 9-12 months after stimulation by either thyroid hormone withdrawal or recombinant human TSH (Tg2); the Access kit was used (functional sensitivity of 0.11 ng/ml); they had undetectable anti-Tg antibodies. Patients were followed up annually. Predictive values were calculated by comparing Tg levels (Tg1 and Tg2) and the outcome in terms of recurrence.

RESULTS

During the median follow-up of 6.2 yr, 32 patients had a recurrence. Assuming a cutoff level for Tg1 at 0.27 ng/ml, Tg1 sensitivity and specificity reached 72 and 86%, respectively, whereas predictive positive and negative values were 20 and 99%, respectively. With a cutoff level for Tg2 at 1.4 ng/ml, sensitivity and specificity reached 78 and 90%, respectively, whereas positive and negative predictive values were 26 and 99%, respectively.

CONCLUSION

This large prospective cohort of patients presented a low rate of recurrence. Initial Tg measurements allow to predict long-term recurrence with an excellent specificity. Stimulated Tg determination presented a slightly higher sensitivity than Tg determination on LT4. TSH stimulation may be avoided when Tg measured 3 months after ablation is less than 0.27 ng/ml during LT4 treatment.

Prognostic factors of disease-free survival after thyroidectomy in 170 young patients with a RET germline mutation: a multicenter study of the Groupe Francais d'Etude des Tumeurs Endocrines

BACKGROUND

In hereditary medullary thyroid carcinoma (HMTC), prophylactic surgery is the only curative option, which should be properly defined both in time and extent.

OBJECTIVES

To identify and characterize prognostic factors associated with disease-free survival (DFS) in children from HMTC families.

DESIGN

We conducted a retrospective analysis of a multi-center cohort of 170 patients below age 21 at surgery. Demographic, clinical, genetic, biological data [basal and pentagastrine-stimulated calcitonin (CT and CT/Pg, respectively)], and tumor node metastasis (TNM) status were collected. DFS was assessed based on basal CT levels. Kaplan-Meier curves, Cox regression, and logistic regression models were used to determine factors associated with DFS and TNM staging.

RESULTS

No patients with a preoperative basal CT <31 ng/ml had persistent or recurrent disease. Medullary thyroid carcinoma defined by a diameter ≥10 mm [hazard ratio (HR): 6.0; 95% confidence interval (95% CI): 1.8-19.8] and N1 status (HR: 20.8; 95% CI: 3.9-109.8) were independently associated with DFS. Class D genotype [odds ratio (OR): 48.5, 95% CI: 10.6-225.1], preoperative basal CT >30 ng/liter (OR: 43.4, 95% CI: 5.2-359.8), and age >10 (OR: 5.5, 95% CI: 1.4-21.8) were associated with medullary thyroid carcinoma ≥10 mm. No patient with a preoperative basal CT <31 ng/ml had a N1 status. Class D genotype (OR: 48.6, 95% CI: 8.6-274.1), and age >10 (OR: 4.6, 95% CI: 1.1-19.0) were associated with N1 status.

CONCLUSION

In HMTC patients, DFS is best predicted by TNM staging and preoperative basal CT level below 30 pg/ml. Basal CT, class D genotype, and age constitute key determinants to decide preoperatively timely surgery.

[Time trends in the geographic variation of thyroid cancer incidence by tumor size from 1983 to 2000 in France]

BACKGROUND

The aim of this investigation was to study geographic time trends of thyroid cancer incidence according to tumor size in France, 1983 to 2000.

METHODS

Incidence data were provided from six French registries over the period 1983-2000 covering seven administrative districts. Five tumor size groups were distinguished: < 10mm, 10-20mm, 20-40mm, > 40mm and unknown size. Papillary cancers diagnosed in women were analyzed according to tumor size in each geographic area. World age standardized rates were calculated and annual percent change rates were estimated for each tumor size group in each geographic area. Loglinear Poisson regression models were used to study geographic discrepancies in time trends incidences.

RESULTS

The six French registries included 2222 papillary thyroid cancers in women between 1983 et 2000. Thyroid cancer incidence was increasing in the six geographic areas. Geographical variations in time trends incidence between registries reflected geographical variations in time trends incidence of small sized tumors (less than 10mm).

CONCLUSION

Wide geographic variations in thyroid cancer incidence were noticed for small size tumors, which may be correlated with geographic variations in medical practices.

Health outcomes of children fathered by patients treated with radioiodine for thyroid cancer

CONTEXT AND OBJECTIVES

Radiation is known to be mutagenic. The present study analyses birth outcomes and the health of offspring from men previously exposed to (131) I treatment for thyroid carcinoma.

METHODS

Data on 493 pregnancies (356 from 173 untreated fathers, 23 from 17 patients who have undergone surgery alone and 114 from 63 fathers who received (131) I) were obtained by interviewing male patients treated for thyroid carcinoma who had not received significant external radiation to the testes. Among these pregnancies, 73 were conceived from fathers who had received more than 370 MBq.

RESULTS

The mean activity for the 114 pregnancies fathered by 63 patients was 3993 MBq leading to an estimated radiation dose of 9.2 cGy to the testes (MIRD committee coefficient). No significant differences between untreated and treated fathers were found for any adverse outcome.

CONCLUSION

There was no evidence that exposure to radioiodine affects the outcome of subsequent pregnancies and offspring, whatever the event considered. As our study is underpowered, the question of whether testicular irradiation, fractionated or not, is linked to impaired fertility or consequences on offspring remains to be established.

Thyroid adenomas and carcinomas following radiotherapy for a hemangioma during infancy

BACKGROUND AND PURPOSE

A cohort study was performed to investigate the carcinogenic effect of treating skin hemangioma with ionizing radiation during early childhood. This paper presents the incidence of differentiated thyroid adenomas and carcinomas after radiotherapy in this cohort.

METHODS AND MATERIALS

Of a total of 8307 patients treated for a skin hemangioma between 1940 and 1973 at the Institut Gustave-Roussy, 4767 were included in an incidence study, among whom 3795 had received radiotherapy. Seventy-three percent were less than 1-year-old at the time of treatment. External radiotherapy, Radium 226, Strontium 90, Yttrium 90, and Phosphorus 32 were used. The radiation dose received by the thyroid during radiotherapy, estimated in 3497 of the 3795 patients using specific software, was 41 mGy on average. Thyroid tumor cases were obtained by sending out a questionnaire, and were verified in pathological reports. Estimates of thyroid cancer specific incidence rates in the French population were obtained from the French cancer registry network. External and internal analyses were performed.

RESULTS

During an average follow-up of 35 years, 11 patients developed a differentiated thyroid carcinoma and 44 a thyroid adenoma. The incidence of thyroid adenoma was found to be higher among taller and heavier individuals. The incidence of both thyroid carcinoma and adenoma was higher among non-smoker patients. A significant dose-response relationship was found between the radiation dose received by thyroid and the risk of thyroid cancer (Excess Relative Risk per GY, ERR/Gy: 14.7, 95%CI: 1.6-62.9) and of adenoma (ERR/Gy: 5.7, 95%CI: 0.7-19.4).

CONCLUSION

This study confirms that radiation treatment performed in the past for hemangioma during infancy increased the risk of thyroid carcinoma and adenoma. Patients treated with external radiotherapy or with Radium 226 applicators for hemangiomas have to be more specifically followed up because this is the subgroup in whom the highest doses were received by the thyroid gland (more than 90% of the radiation doses were higher than 100 mGy). They are therefore more at risk of developing thyroid cancer.

SPECT/CT in localization of parathyroid adenoma or hyperplasia in patients with previous neck surgery

PURPOSE

Single photon emission computed tomography/computed tomography (SPECT/CT) now makes it possible to use combined morphologic CT and functional scintigraphy information. It has proved useful for localization of abnormal parathyroid glands, especially in the case of an ectopic gland. We experienced that it was also beneficial for patients with a history of previous neck surgery, and we report 4 cases in this entity.

MATERIALS AND METHODS

Four patients with prior neck surgery and hyperparathyroidism underwent parathyroid Tc-99m MIBI scintigraphy with SPECT/CT. Two patients had undergone surgery for hyperparathyroidism and 2 had undergone thyroidectomy, 1 for thyroid cancer and 1 for multinodular goiter. Parathyroid hormone levels were assessed during surgery, and patients were followed several months after treatment.

RESULTS

SPECT/CT successfully localized the abnormal gland, including an uncommon anterior situation for which previous surgery guided by planar imagery failed to cure the hyperparathyroidism. It allowed efficient surgical treatment, as confirmed by parathyroid hormone level normalization, without complications and with a relatively short operation time in those challenging cases.

CONCLUSIONS

SPECT/CT seems to be a useful tool for presurgical assessment in hyperparathyroidism, not only for ectopic glands but also for patients with previous neck surgery.

Comparison of seven serum thyroglobulin assays in the follow-up of papillary and follicular thyroid cancer patients

BACKGROUND

Serum thyroglobulin (Tg) is the marker of differentiated thyroid cancer after initial treatment and TSH stimulation increases its sensitivity for the diagnosis of recurrent disease.

AIM

The goal of the study is to compare the diagnostic values of seven methods for serum Tg measurement for detecting recurrent disease both during L-T4 treatment and after TSH stimulation.

METHODS

Thyroid cancer patients who had no evidence of persistent disease after initial treatment (total thyroidectomy and radioiodine ablation) were studied at 3 months on L-T4 treatment (Tg1) and then at 9-12 months after withdrawal or recombinant human TSH stimulation (Tg2). Sera with anti-Tg antibodies or with an abnormal recovery test result were excluded from Tg analysis with the corresponding assay. The results of serum Tg determination were compared to the clinical status of the patient at the end of follow-up.

RESULTS

Thirty recurrences were detected among 944 patients. A control 131I total body scan had a low sensitivity, a low specificity, and a low clinical impact. Assuming a common cutoff for all Tg assays at 0.9 ng/ml, sensitivity ranged from 19-40% and 68-76% and specificity ranged from 92-97% and 81-91% for Tg 1 and Tg2, respectively. Using assays with a functional sensitivity at 0.2-0.3 ng/ml, sensitivity was 54-63% and specificity was 89% for Tg1. Using the two methods with a lowest functional sensitivity at 0.02 and 0.11 ng/ml resulted in a higher sensitivity for Tg1 (81% and 78%), but at the expense of a loss of specificity (42% and 63%); finally, for these two methods, using an optimized functional sensitivity according to receiver operating characteristic curves at 0.22 and 0.27 ng/ml resulted in a sensitivity at 65% and specificity at 85-87% for Tg1.

CONCLUSION

Using an assay with a lower functional sensitivity may give an earlier indication of the presence of Tg in the serum on L-T4 treatment and may be used to study the trend in serum Tg without performing any TSH stimulation. Serum Tg determination obtained after TSH stimulation still permits a more reliable assessment of cure and patient's reassurance.

A time trend analysis of papillary and follicular cancers as a function of tumour size: a study of data from six cancer registries in France (1983-2000)

The incidence of thyroid cancers, and in particular the papillary forms, has been increasing sharply for many years in Western countries. However, the factors explaining this increase have not been clearly established. Some studies mention the effects of radioactive fallout, particularly after the accident in Chernobyl. Another probable cause is related to progress in medical practice, and particularly in diagnosis. In this article, we describe time trends in the incidence of papillary and follicular cancers, taking into account the size of the tumour at the time of diagnosis. The analysis was carried out on cases from six French cancer registries for the period 1983-2000. Anatomopathological reports concerning 3381 cancer cases were systematically recoded and centralised, following ICDO-3 rules. Over the whole period, the annual percent change of the incidence of papillary cancers was +8.13% and +8.98%, respectively in men and in women. For micropapillary carcinomas (< or = 10 mm), this increase was respectively +12.05% and +12.85%. There is no significant effect of period apart from micropapillary carcinomas in women. However, a birth cohort effect exists for some groups. This effect corresponds to an acceleration in the risk for people born after the 1930s. For the most recent period (1998-2000), half the cases of papillary cancer were micropapillary carcinomas, and for one third of these, the tumour was < or = 5 mm. Our description of a time trend of incidence as a function of tumour size supports the hypothesis of the role of medical practice in a context of high prevalence. Obviously, these findings do not exclude the possible role of other factors.

[Predictive value and sensibility of hospital discharge system (PMSI) compared to cancer registries for thyroïd cancer (1999-2000)]

BACKGROUND

Cancer registries have a complete recording of new cancer cases occurring among residents of a specific geographic area. In France, they cover only 13% of the population. For thyroid cancer, where incidence rate is highly variable according to the district conversely to mortality, national incidence estimates are not accurate. A nationwide database, such as hospital discharge system, could improve this estimate but its positive predictive value and sensibility should be evaluated.

METHODS

The positive predictive value and the sensitivity for thyroid cancer case ascertainment (ICD-10) of the national hospital discharge system in 1999 and 2000 were estimated using the cancer registries database of 10 French districts as gold standard. The linkage of the two databases required transmission of nominative information from the health facilities of the study. From the registries database, a logistic regression analysis was carried out to identify factors related to being missed by the hospital discharge system.

RESULTS

Among the 973 standardized discharge charts selected from the hospital discharge system, 866 were considered as true positive cases, and 107 as false positive. Forty five of the latter group were prevalent cases. The predictive positive value was 89% (95% confidence interval (CI): 87-91%) and did not differ according to the district (p=0,80). According to the cancer registries, 322 thyroid cancer cases diagnosed in 1999 or 2000 were missed by the hospital discharge system. Thus, the sensitivity of this latter system was 73% (70-76%) and varied significantly from 62% to 85% across districts (p<0.001) and according to the type of health facility (p<0.01).

CONCLUSION

Predictive positive value of the French hospital discharge system for ascertainment of thyroid cancer cases is high and stable across districts. Sensitivity is lower and varies significantly according to the type of health facility and across districts, which limits the interest of this database for a national estimate of thyroid cancer incidence rate.